In video quality assessment, there is a need in some cases to detect whether a frame in a video bitstream is a gradual transition picture, including for example, a fade-in and fade-out picture and a cross-field picture.
Conventional solutions for detecting gradual transition pictures work in pixel domain.
However, in some application scenarios, pixel information is not available for the detection of a gradual transition picture. For example, in P.NBAMS (Non-intrusive bitstream model for the assessment of performance of video streaming) of ITU-T, the quality of a video bitstream will be assessed at a Set-Top-Box without decoding the video bitstream into pixel level. In this case, the detection of a gradual transition picture in the video bitstream has to be done at the level of compressed video bitstream.